1) As Google search sent me to "googlebugs" which in it's turn sent me here, where i've found no link to standartized form for bug report, so i've posted here. Any input how to do it properly?

2) I didn't changed date format recently (even don't know where to do so) and i didn't used "custom range" before.

3) typed words for search -> choosed date range -> clicked on shown range to edit it -> found that days and months are swapped -> choosed date from calendar (not typed it) -> found that search is wrong. IMO it is a problem.